Development and validation of a multi-residue extraction method for the determination of organic micropollutants in surface water

The water pollution assessment to evaluate environmental quality standard on compliance with European Directive 2013/39/EU needs complex analytical approaches to satisfy legislation requirements about quantification of a wide range of pollutants, with different physicochemical properties and concentration levels (trace or ultra-trace). To accomplish this task, a multi-residue method for screening, quantification and confirmation of multiclass pollutants in surface water has been developed. It is based on an integrated approach where solid phase extraction (SPE), gas chromatography–mass spectrometry (GC–MS), gas chromatography–tandem mass spectrometry (GC–MS/MS) and liquid chromatography– tandem mass spectrometry (LC–MS/MS) are simultaneously employed. Target compounds, including several groups of emerging and persistent contaminants (as defined in the 2000/60/EC European Water Framework Directive) and, specifically, polycyclic aromatic hydrocarbons (PAH), phthalate, alkylphenols, polybrominated biphenyl ethers (PBDE), chlorophenols and chloroalkanes were investigated. The multi-residual method was validated according to DLG n°19/2010 with regards to two different concentration levels. According to the Environmental Quality Standard (EQS) they are defined as (i) the maximum concentration of a substance in natural water that does not affect the quality of water and (ii) the limit of quantification (LOQ), which must be lower than 1/3 of EQS. Recovery rates of SPE were from 62 to 105%. Precision of method, calculated as relative standard deviation (RSD), was below 27% for most of tested compounds. In conclusion, this method allows for rapid and reliable determination of different classes of organic micropollutants present at trace and ultra-trace levels in complex water matrices, such as surface water.